1 /* Licensed under LGPLv2.1+ - see LICENSE file for details */
7 * struct io_plan - a plan of what I/O to do.
8 * @pollflag: POLLIN or POLLOUT.
9 * @io: function to call when fd is available for @pollflag.
10 * @next: function to call after @io returns true.
11 * @next_arg: argument to @next.
12 * @u: scratch area for I/O.
14 * When the fd is POLLIN or POLLOUT (according to @pollflag), @io is
15 * called. If it returns -1, io_close() becomed the new plan (and errno
16 * is saved). If it returns 1, @next is called, otherwise @io is
17 * called again when @pollflag is available.
19 * You can use this to write your own io_plan functions.
23 /* Only NULL if idle. */
24 int (*io)(int fd, struct io_plan *plan);
25 /* Only NULL if closing. */
26 struct io_plan (*next)(struct io_conn *, void *arg);
66 * io_debug_conn - routine to select connection(s) to debug.
68 * If this is set, the routine should return true if the connection is a
69 * debugging candidate. If so, the callchain for I/O operations on this
70 * connection will be linear, for easier use of a debugger.
72 extern bool (*io_debug_conn)(struct io_conn *conn);
75 * io_debug - if we're debugging the current connection, call immediately.
77 * This determines if we are debugging the current connection: if so,
78 * it immediately applies the plan and calls back into io_loop() to
79 * create a linear call chain.
81 struct io_plan io_debug(struct io_plan plan);
84 * io_debug_io - return from function which actually does I/O.
86 * This determines if we are debugging the current connection: if so,
87 * it immediately sets the next function and calls into io_loop() to
88 * create a linear call chain.
90 int io_debug_io(int ret);
93 * io_plan_no_debug - mark the next plan not to be called immediately.
95 * Most routines which take a plan are about to apply it to the current
96 * connection. We (ab)use this pattern for debugging: as soon as such a
97 * plan is created it is called, to create a linear call chain.
99 * Some routines, like io_break(), io_duplex() and io_wake() take an
100 * io_plan, but they must not be applied immediately to the current
101 * connection, so we call this first.
103 #define io_plan_no_debug() ((io_plan_nodebug = true))
105 extern bool io_plan_nodebug;
107 static inline struct io_plan io_debug(struct io_plan plan)
111 static inline int io_debug_io(int ret)
115 #define io_plan_no_debug() (void)0
118 #endif /* CCAN_IO_PLAN_H */